[perl #114696] [BUG] $_ variable disappears after Rakudo sees block in for @array -> $variable {}

[Christian Bartolomaeus via RT]

Since this works as expected, I added a test to 
S04-declarations/implicit-parameter.t with the following commit: 
https://github.com/perl6/roast/commit/7192d95e4b and I'm closing this ticket.